Four heptamethine cyanine dyes with active hydroxyl groups were prepared using 2,3, 3-trimethylindolenine and 1,1, 2-trimethyl-1H-benzo [e] indole as raw materials. Firstly, two kinds of quaternary ammonium salts were synthesized, then they were condensed with 2-chloro-1-formyl-3-hydroxymethyl cyclohexene respectively. Lastly, C-C substitution in dye medium was achieved by Suzuki-Miyaura coupling reaction. The dye structures were characterized by 1HNMR and FTMS spectra;The absorption spectra of four dyes were determined by UV-vis with ethanol as solvent;The high voltage xenon lamp with current of 13.4A was used as the source of the lamp to study the light resistance of the dyes;Investigated the effect of pH value on dye color and deduced the mechanism of color change. The results showed that the four kinds of four heptamethine cyanine dyes have strong absorption in the near infrared region, and have good light stability in anhydrous ethanol. The study on the spectral properties of dyes at different pH values found that the absorption spectrum of four heptamethine cyanine was greatly affected by pH, and the dyes have the best absorption in the near infrared region when the pH value is 5~7.